基本思路
简单的思路,就是首先交换
root->next
和revert_root
的指向,此时已经逆置了一个元素
但是
root
和revert_root
就反了,再交换下就 ok 了
直接上代码
/*
Author: SpringHack - springhack@live.cn
Last modified: 2019-04-02 01:32:40
Filename: main.c
Description: Created by SpringHack using vim automatically.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// Test data
int test_data[] = {
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
};
// Node struct
typedef struct _node {
int value;
struct _node* next;
} node_item;
// Just easy to use malloc
typedef node_item* node;
// Define linked list root and reverted linked list root
// Only two variables needed to revert a linked list
static node root = NULL;
static node revert_root = NULL;
int main() {
// Create linked list
{
int i = 0, count = sizeof(test_data) / sizeof(int);
node tmp;
while (i < count) {
if (!root) {
root = (node)malloc(sizeof(node_item));
tmp = root;
} else {
tmp->next = (node)malloc(sizeof(node_item));
tmp = tmp->next;
}
tmp->next = NULL;
tmp->value = test_data[i];
++i;
}
}
// Print linked list
{
node tmp = root;
while (tmp) {
printf(tmp->next ? "%d " : "%d", tmp->value);
tmp = tmp->next;
}
printf("\n");
}
// Revert linked list
{
while (root) {
if (!revert_root) {
revert_root = root;
root = root->next;
revert_root->next = NULL;
} else {
revert_root = (node)((intptr_t)revert_root ^ (intptr_t)root->next);
root->next = (node)((intptr_t)revert_root ^ (intptr_t)root->next);
revert_root = (node)((intptr_t)revert_root ^ (intptr_t)root->next);
revert_root = (node)((intptr_t)revert_root ^ (intptr_t)root);
root = (node)((intptr_t)revert_root ^ (intptr_t)root);
revert_root = (node)((intptr_t)revert_root ^ (intptr_t)root);
}
}
}
// Print reverted linked list
{
node tmp = revert_root;
while (tmp) {
printf(tmp->next ? "%d " : "%d", tmp->value);
tmp = tmp->next;
}
printf("\n");
}
return 0;
}